Before getting down to the more interesting stuff, lets get one thing out of the way: In my humble opinion, Apples move to Intel processorsseems quite coherent from a hardware perspective.
As a Mac user since 1984, I have lived through every step of the Macintosh hardware saga, and it is sad to say, the huge performance benefits that were promised from the different generations of chips never totally materialized.
I love my G5. It is faster than a high-end PC for some tasks, but it is also slower for some others. In other words, the whole platform-performance thing is a tie, and the G5 has not evolved anywhere near as fast as initially promised by Apple. (And lets not even discuss the painful issue of the nonexistent G5 PowerBooks.) Somewhere along the line, things just havent worked out as advertised.
Of course Im not a developer, and I can see that the transition will present a challenge and require some additional resources, but from a users perspective, nothing should change; Tiger will still look like Tiger. The Mac UI wont feel different because its running on Intel silicon. And we can trust Apple to come up with a catchy name and clever marketing for the next high-end Macintosh platform.
As for the hard-core enthusiasts now proclaiming that they will never buy Apple again, what arethey going to chose as their computing platform? Longhorn, if and when it ships? Linux? Xbox 360?